More back extension (both lumbar & thoracic), a little more depth (maybe 2"), get a rack and a barbell.
Here is my recent squat effort, with 45 lbs each arm (don't have a rack yet.) Have already maxed out the PowerBlock. I have a weight vest I can add.
Any comments on improving my form?
squat video 3-16-13 - YouTube
More back extension (both lumbar & thoracic), a little more depth (maybe 2"), get a rack and a barbell.
Don't lean over so far, you should be pretty much straight up hinging at your hips. Also, deeper, your ass should touch your calves.
Keep your back straighter...like your t-shirt should face the ceiling, not floor
There's no squat in Olympic weightlifting. There's the snatch and there's the clean-and-jerk. You never have and never will see a squat contested in the Olympics.
Powerlifting-legal squats (the only competitive squat that exists to my knowledge) are required to reach parallel (which I already defined above, and suggested going deeper than by 1-2 inches).